Control system



C. W. NESSELL CONTROL SYSTEM Aug. 16, 1938.

Filed Dec. 16, 1936 2 Sheets-Sheet 1 STORAGE BATTERY CZarerzce WNesseZZ Aug. 16, 1938.

c. w. NESSELL C ONTROL S YS TEM Filed Dec. 16, 1936 2 Sheets-Sheet 2 CZarevzce WilfesseZZ Patented n. 16, 1938 PATENT orrlcs CONTROL SYSTEM Clarence W. Nesscll, Dayton, Ohio, assignmto Minneapolis-Honeywell Regulator Company, Minneapolis, Minn, a corporation of Delaware Application December 16, 1936, SerialNo. 116,189

2 18 Claims. (Cl. 290-30) This invention relates to load control means for internal combustion engines, and is more particularly concerned with automatically controlled engine driven generating units such for instance .5, as employed for lighting purposes.

In lighting systems such as used for lighting 15; ing the lighting system out of service during the daytime. The controllers are also provided with recycling apparatus for causing starting of the reserve generating unit in the event that the other unit fails to start, or stops running, this recycling go apparatus acting to alternately attempt to start each unit until one of the units starts.

Apparatus of this type operates satisfactorily during warm or relatively mild weather. in cold weather, however, dimculties are encountered, in 25- that the automatic control mechanism, while causing starting of one unit permits the lighting load to be thrown upon that unit before its engine has become sumciently warm to carry the load.

This results in stalling of the unit. The auto- 30 matic controller then recycles and attempts to start the reserve unit. When that unit starts, the lighting load thrown upon it acts to stall it in the same manner as the first unit stalled. After stalling of the second unit, the controller recycles,

35- causing starting of the first unit, and when thatunit starts, it again stalls. This recycling process a is then continuously repeated, the engines alternately starting and stalling until the starting batteries are discharged.

as it is therefore a primary object of my invention to provide an arrangement for overcoming the dlfilculty aforementioned. More particularly, it is an object of my invention to provide in a system of the type mentioned a means for preventing the 45 load from being thrown on a generating unit until the operation of its engine is sufliciently satisfactory as to enable it to carry the load. A further object is to provide a novel control arrangement for automatically starting an in- 50 ternal combustion engine and for placing the load upon said engine only when its temperature becomes sufliciently high to ensure its carrying the load without stalling.

other objects will appear as this description 55 proceeds.

Where complete automatic For a detailed description of my invention, reference is made to the accompanying drawings, in which: Y

Figure 1 is a diagrammatic view showing one form' which my invention may take; and

Figure 2 is a diagrammatic view of a modification.

Referring to Figure 1, reference characters I and 2 indicate engine driven generating units. Generating unit I consists of an internal combustion engine 3' driving an electric generator 4. The generating unit 2 consists of a similar engine 3a driving a generator 5. Internal combustion engine 3 is provided with a radiator 6 and the usual hot and cold water connections l and 8 respectively. The engine 30 is provided with a similar radiator 611, this radiator being connected to the engine by pipes in. and 8a.. Generating unit I is provided with the usual control panel 9 while the generating unit 2 is provided with an identical panel H, these panels containing the usual control switches, relays, circuit breakers, and meters as is well known in the art. Control panel 9 of generating unit .l is provided with output terminals M, the left-hand terminal being indicated as positive and the right-hand terminal being indicated as negative. The control panel l l oi generating unit 2 is provided with output terminals it which are identical with terminals I3 of panel s.

The generating units 9 and 2 are preferably provided with starting mechanism of the type which acts to automatically start the units whenever a load is thrown across the output terminals of the control panels. This type of startingmechanism is well known in the art and forms no part of my invention. Hence no detailed closure or this type or starting mechanism is necessary here. For starting purposes the control panels 9 and ii are provided with battery terminals it and it, respectively. These battery terminals are connected to a storage battery 3. The left-hand or positive terminal l9 of storage battery it is connected by wires 2!! and 2! with the right-hand battery terminal l of control panel a. Thissame battery terminal is also connected by wires 20 and 22 with the right-hand battery terminal I6 of control panel ll. 'I'he right-hand or negative terminal 23 of storage battery I8 is connected by wires 24 and 25 with the left-hand battery terminal l5 0! control panel 9, and is also connected to the left hand battery terminal l8 of control panel II by a wire 28. Whenever a load is placed across the output terminals of either unit, the starting mechanism for that unit will act to connect battery l8 to the generator of that unit to cause said generator to run as a motor for starting its engine. The control mechanism for each unit is also such that the unit will be maintained in operation so long as a load is placed across the generator terminals.

When the load is removed, the control mechanism acts to automatically stop the engine. In other words a load is thrown across the generator terminals of either unit, the control mechanism for that unit will cause the unit to start and run until the load is taken off the generator, at which time the unit will stop.

In order to maintain the motors 3 and 3a above a predetermined temperature during cold weather, each motor is provided with a thermostat generally indicated at 30. The thermostats each consist of an expansible bellows 3| connected by a tube 32 to a thermostatic element, not shown, located in the cold water pipe 8 or 6a. The bellows 3|, tube 32, and thermostatic element are filled with a suitable volatile fluid as is well known in the art. Mounted above the ex pansible bellows 3| of each thermostat is a mercury switch carrier 33 pivoted at 34. Upon the mercury switch carrier 33 of generating unit I is mounted a mercury switch 35 or known form.

The mercury switch carrier 33 of generating unit 2 carries a similar mercury switch 35a. In the crank case of engine 3 is located a heating element 36, a similar heating element 36a being located in the crank case of engine 3a. One terminal of heating element 36 is connected to the negative output terminal of control panel 9 by wires 31 and 38. The other terminal of heating element 36 is connected to one contact of mercury switch 35 by a wire 39. The other terminal of mercury switch 35 is connected by a wire to the positive output terminal l3 of control panel 6. The heating element 36a is similarly connected to mercury switch 35a and to the positive output terminals 4 of control panel The arrangement is such that should the temperature of the water of engine 3 fall below a predetermined value, the bellows 3| of thermostat 3|] will contract sufficiently to cause tilting of mercury switch to closed position. This will complete a circuit from the positive terminal I3 of control panel 9 through wire 46, mercury switch 35, wire 39, heating element 36, wire 38 and wire 31 to the negative terminal oi. control panel 9.

The heating element 36 will thus be thrown across the generator output terminals l3. The control mechanism for generating unit I will then act to cause starting of the engine 3, the output of the generator 4 causing the heating of heating element 36. Engine 3 will then run to warm up, and during this running period its output will be consumed by the heating element 36 which acts to heat the oil in its crank case. As the motor warms up, the pressure within the thermostatic element 8 will increase, this pressure acting through the tube 32 to cause expansion 01' the bellows 3|, this in turn causing tiltcause operation 01' said engine and heating of the oil in the crank case thereof until the engine temperature reaches a predetermined value, at which time the engine will be stopped by opening of mercury switch 350. It will be seen, therefore, that the thermostats 30 or each unit act to prevent the temperature of these units from falling below a predetermined minimum temperature in order to insure ready starting of the units in cold weather.

Located in the water reservoir of the radiator 6 of generating unit I is a thermostat generally indicated at 40. This thermostat comprises an expansible and contractable chamber or bellows 4| connected by means of a tube 42 to the thermostatic element 43 located in the radiator. Chamber 4|, tube 42 and element 43 are filled with a suitable volatile fluid as is well known in the art. A mercury switch carrier 44 is mounted above the chamber 4| and is pivoted at 45, this mercury switch carrier having mounted thereon a mercury switch 46. When the temperature in the radiator 6 is below a predetermined value the switch carrier 44 will assume the position shown. Upon rise in temperature, however, the bellows 4| will expand due to increase in pressure of the volatile fluid in thermostatic element 43, this causing tilting of the mercury switch 46 towards open position. When the temperature reaches a predetermined value the mercury switch will be tilted sufliciently to cause opening of its contacts. A thermostatic switch 40a similar to the thermostat 40 is provided for the radiator 6a and engine 3a. The construction and operation of thermostatic switch 40a is identical with that of thermostat 4|]. The purpose of thermostats 46 and 40a will appear as this description proceeds.

The engine 3 is also provided with a thermostat generally indicated at 50. Thermostat 50 is similar in construction to thermostat 46, it being provided with an expansible and contractable bellows 5|, a tube 52, and a thermostatic element 53 responsive to the engine temperature. Actuated by the bellows 5| is a mercury switch 56 which is carried by a switch carrier 55. The arrangement of thermostat 50 is suchthat when the engine temperature is below a predetermined value, the bellows 5| will becontracted sufllciently to cause closure 01' the switch. When, however, the engine temperature becomes too high for safe operation, the bellows 5| will expand sufllciently to cause opening of the mercury switch. The engine 3a of generating unit 2 is provided with a similar thermostat 500, the construction and operation or which is identical with that of thermostat 50.

Reference characters 6| and 62 indicate beacon lights such as used for airport landing fields. These beacon lights are connected in parallel. The negative output terminals of control panels 9 and H are connected together and to one terminal oi beacon lights 8| and 62. Tracing. these connections, the negative terminal I3 is connected by wires 31, 38, 63 and 64 to the negative terminal H of control panel The left-hand terminal of beacon 6| is connected by a wire 65 to wire 63 while the left-hand terminal of beacon 62 is connected to the junction of wires 63 and 64 by a. wire 66. The other terminals of the beacons 6| and 62 are connected together by wires 81 and 68, the wire 61 leading to the output terminal of clock control mechanism 10 in a manner to be hereafter described.

The function of the clock control mechanism 10 is to start either unit I or unit 2 at approxi- 3 and III.

mately sundown to cause fighting of the beacons BI and 62, and to shut down the unit at sunrise. This clock mechanism further functions to operate units I and 2 alternately, that is, to operate unit I during one night and to operate unit -2 during the following night. The clock mechanism further functions in case of failure of one engine to start the idle engine The mechanism for performing'these functions will now be described in detail. In general it comprises a clock switch mechanism generally indicated at H, a time and recycling mechanism generally indicated at 12, and a potential relay 13.

The clock switch mechanism 1I comprises a suitable timing mechanism 14 havinga shaft 15 upon which is mounted a disc 18 formed of insulating material. Mounted upon disc 18 is a first switch arm 11 and a second switch arm 18. The timing mechanism 14 is designed to rotate the shaft 15 and the disc 16 in a counter-clockwise direction one revolution every 24 hours. Cooperating with the .switch arm 11 are arcuate contact segments 19, 88 and 8!. Contact segments 19, 88 and ill are suitably mounted and insulated from each other and the contact segment 19 subtends an are equal to the arc subtended by the combined contact segments 88 and iii. The arrangement is such that as the disc 16 is rotated in a counter-clockwise direction, the switch arm 11 will first engage contacts I9 and 88. Upon continued movement of switch arm 11 it will disengage from'contact 88 and engage with contact 8| thus breaking the connection between contacts 19 and 88 and connecting contact 19 with contact M. The switch arm 18/ is arranged to cooperate with two arcuate contact segments 82 and 83. It is to be understood that contacts I9, 88 and BI! are displaced axially of contacts 82 and 83 to prevent the switch arm 11 from engaging contacts 82 and 83, and to prevent the switch arm 18 from engaging the contacts 18, 88 and BI. The spacing ofthe contact arms and various contact segments is such that the switch arm 11 will engage contacts I9 and 88 at the same time that switch arm 18 engages contacts 82 and 83,, the setting of disc 16 on shaft i being such that this action will occur at sunset. The contact segment 18 is connected by means of the wire 28 with the positive terminal E9 of the storage battery it. The switch. arm 'ii together with contacts 89 and 88 thus comprises a battery switch for disconnecting the storage battery I8 from the control device to be hereafter described during the daytime. The contact segment 83 is connected to a resistance 85, the other terminal of this resistance being connected by wire -88 to wire 83 which leads to the negative output terminals of control panels The contact segment 82 is connected through a selector switch to be hereafter de scribed, which switch connects segment 82 with one or the other of the positive output terminals of control panels 9 and I I. The switch arm 18 and the contacts 82 and 83 thus form a switch for disconnecting the starting resistance 85 from the control panels during the daytime and per-' mitting connection of the starting resistance therewith at sunset and during the night.

The timing or recycling mechanism 12 consists of a direct current series wound motor 98, the armature, 98a of which is connected to a shaft 9I. Mounted upon the shaft 8| is a gear train indicated at 92, the last gear of which drives a shaft 93. Mounted upon shaft 93 are switch arms 94, '95, 98 and-91. Cooperating with the tire 360 degrees of rotation of said switch arm.

Radially spaced from the annular contact I88 are four arcuate contact segments I8I, I82, I83 and I84, these segments being disposed respectivelyin the first, second, third and fourth quadrants. The arrangement of these contact segments is such that when the switch arm 96 is in a vertically upward position it engages the contact segment It. When the contact arm 96 is rotated counter-clockwise through an angle of 90 degrees to a horizontal position, it disengages contact MI and engages contact I82. Upon movement of arm 96 through another 90 degrees to a vertically downward position it disengages contact I82 and engages the contact segment I83. Upon movement of the switch arm through another 90 degree angle it disengages contact segment I83 and engages the segment I84. Mounted in the same quadrants with the contact segments I82 and I88 and radially spaced therefrom are arcuate contact segments I85 and I86, the purpose of which will become apparent later. The contact segments I8I and I83 are connected together by a wire II8. this wire being connected by wires III and H2 to the contact segment 88 of the switching mechanism 1I. As pointed out hereinbefore, the contact segment 19 is connected to the positive terminal I9 of storage battery I8. Therefore, when switch arm Ti engages contacts 19 and 88 it connects the contacts I M and I83 to the positive terminal of the storage battery. The contact segment I88 is connected by a wire H5 to the series field H6 of the driving motor.

The other terminal of the driving motor is connected by a wire I I1 to a resistance I I8 the other end of resistance IIB being connected by wires H9 and 24 to the negative terminal 23 of the storage battery I8. The contact segments I 82 and I88 are connected together by wires I28 and IN, the wire I28 leading to the contact I22 of the potential relay 13. The switch arm I23 of potential relay 13 is connected by wires I28 and Hz to the contact segment 88 of the battery switch. It will be seen, therefore, that when the switch arm I123 of the potential relay 13 engages the contact I22 the arcuate contact segments I82 and I88 are connected to the positiveside of the storage battery along with the contact segments mi and I83.

With the parts in the position shown, (assuming switch arm '61 to be engaging contact segments 19 and'88) an energizing circuit for the motor will be completed, this circuit being traced as follows: positive terminal I8 of storage battery I8, wire 28, contact segment 19, switch arm I1, contact segment 88, wire II2, wire III, wire H8, contact segment I85, switch arm 96, annular contact I88. wire H5, series fields H6, armature 98a, wire II'i, resistance I I8, wire II9 and wire 28 to negative terminal 23 of the storage battery. This will cause rotation of the motor in a direction to rotate the switch arm 96 (and also contact arms 94, 95 and 91) in a counter-clockwise direction. When the switch arm 96 is rotated through an angle of 90 degrees, it rides ofi contact segment IM and engages the contact segments I82 and I85. Unless at this time the potential relay switch arm I23 is engaging contact I22 the motor driving circuit will be broken thus causing the motor to stop with the switch arm 96 in a horiwith the contact arm I22.

apparent that the switch arm 36 and the conzontal position between the first and second quadrants. If, however, the contact arm I23 01 the potential relay I3 is engaging contact I22, a circult will be completed from wire II2 through switch arm I23, contact I22 and wire I20 to the contact segment I02. This will cause energization of the driving motor through the switch arm and contact I00, and the motor will thus contintie to operate until either the potential relay switch is opened or until the switch arm 36 rides of! contact segment I02 and engages the contact segment I03. However, in the latter case, as the contact segment I03 is connected directly to the battery switch by wires IIO, III and H2 in the same manner as contact segment IN, the motor will continue to be energized and will rotate through another 90 degrees until switch arm 36 rides on contact segment I03 and rides upon the contact segments I04 and I06. As the contact segment I04 is connected in parallel with segment I02 the action will be the same when switch arm 36 rides from contact segment I03 to contact segment I04 as occurred previously when the contact arm 36 rode from contact IN to contact I02. That is, the motor will stop unless the switch arm I23 of potential relay I3 is in engagement It should therefore be tact segments I00 to I04 comprise a controlling switch for the driving motor, this switch acting to cause the driving motor to stop with the switch arm 36 in a horizontal position or in the second or fourth quadrants in the event that the potential relay I3 is open, or to cause continuous rotation of shaft 33 and switch arm 36 in the event that the potential relay remains closed. The contact segments I05 and I06 are connected together by means of wires I300 and I3I which are connected to the wire I30 leading to the contact segment 8i of the clock switch mechanism II The purpose of these contacts and the connections described will be stated in detail under Operation.

The switch arm 34 cooperates with an annular contact I32 and two arcuate contact segments I33 and I34. Contact segment I33 islocated in the first quadrant and is arranged to be contacted by switch arm 34 when said arm is in a. vertical position as illustrated. The contact segment I33 is also arranged so that'when switch arm 34 is moved through an angle of 90 degrees to a horizontal position it just disengages contact segment I33. The contact segment I34 is located in the third quadrant and is arranged so that when switch arm 34 moves to a vertical position 180 degrees from that illustrated, it will just engage said contact segment. When switch arm 34 moves through another 90 degrees of rotation to a horizontal position itwill Just disengage from contact segment I34. The annular contact I32 is connected by a wire I35 to the contact segment II of the clock switch mechanism IL Contact segment I33 is connected by a wire I36 to the positive output terminal of the control panel 6, and the contact segment I34 is connected by wire "I to the positive output terminal of the control panel I I. Thus when the switch arm I6 of the clock switch mechanism engages the contact segments 62 and 63 and when the switch arm 34 engages contact segments I32 and I33 the starting resistance 63 is connected across the terminals of the control panel 3 of generating unit I. Similarly, when the switch arm 94 engages the contact segments I32 and I34 the starting resistance is connected across "the output terminals I4 of the control panel I I of generating unit 2. It will connected to generating unit 2.

be apparent, therefore, that the switch arm 34 and the contact segments I32, I33 and I34 comprise a selector switch for placing the starting load 85 across the output terminals of either generating unit.

The switch arm 91 cooperates with an annular contact I40 and with arcuate contact segments MI and I42. The contact segment I is located in the second quadrant and is arranged to be Just contacted by the switch arm 91 when said arm moves counter-clockwise to an angle of 90 degrees from that illustrated. The contact segment I4I is also so arranged that when arm 91 moves to a vertical downward position it will just disengage therefrom. The contact segment I42 is similarly arranged in the third quadrant. The contact segment "I is connected by wires I43 and I36 to the positive output terminal of the control panel 9 of generating unit I, while the contact segment I42 is connected by wires I44 and H1 to the positive output terminal of the control panel II of generating unit 2. The annular contact I40 is connected by a wire I45 to one terminal of a mercury switch I46. The other terminal of the mercury switch is connected by a wire 61 to the beacons 6| and 62. It should therefore be apparent that when switch arm 91 engages contacts I40 and HI the beacon lights are connected to the generating unit I while when said switch arm engages contacts I40 and I42 the beacons will be The switch arm 91 and the contact segments I40, I and I42 therefore form a switch for placing the beacon light load upon one generating unit or the other, or for disconnecting the beacon lights from both generating units.

The switch arm 35 cooperates with an annular contact I and with arcuate contact segments I5I and I52. The contact segments I5I and I52 are located in the second and fourth quadrants respectively and are arranged to be contacted by switch arm 95 when said arm is in a horizontal position or in the second or fourth quadrants. The segments, however, arearranged so that when the switch arm 95 is in a vertical position.

there will ,be no engagement. The functions of oted at one end at I63 and at its other end engages with a slot I64 of the mercury switch carrier I65. Mercury switch carrier I65 carries the mercury switch I46 and is pivoted at I66. When relay coil I6I is energized it pulls lever I62 in a counter-clockwise direction, this in turn tilting the mercury switch carrier I65 in a clockwise direction to move the mercury switch to open position. When, however, the relay coil I6I is deenergized the lever I 62 is moved in a clockwise direction under the action of gravity or springs, not shown. This causes tilting of mercury switch carrier I65 in a counter-clockwise direction, thus tilting the mercury switch I46 to circu t closing position. shunting the terminals of the mercury switch I46 is a lamp or other form of resistance element I6I, the purpose of which will hereafter become apparent.

The left-hand end of the relay coil I H is connected by a wire II0 to the wire II2 which is in turn connected to the contact segment of the end of relay coil I6I is connected to the positive terminal I9 of the storage battery I8 when switch arm 11 of the battery switch engages the contact segments 19 and 80. The right-hand end of the relay coil I6I is connected by a wire I1I to one terminal of the mercury switch 46a of temperature controller 4011 located in the radiator of generating unit 2. The other terminal ofswitch 46a is connected by a wire I12 to one terminal of the mercury switch 46 of the temperature controller 40 located on the radiator of generating unit I. The other terminal of mercury switch 46 is connected by a wire I13 to wire 24 and hence to the negative terminal of the storage battery I8. As pointed out hereinbefore, the thermostatic controllers 40 and 40a act to maintain the switches 46 and 46a in closed position when the temperature of the corresponding engine is below proper operating temperature. When the temperature of either unit increases to a proper op-.

erating value the thermostat 40 or 40a of that unit will act to open its switch. When botlr'machines are below proper operating temperature both switches 46 and 46a will thus remain in closed position. This will .complete a circuit through relay coil I6I, this circuit being traced as follows: positive terminal I9'of battery I8, wire 20, contact 19, switch arm 11, contact 80, wire II2, wire I10, relay coil I6I, wire "I, mercury switch 46a, wire I12, mercury switch 46, wire I13 and wire 24 to the negative terminal of storage battery I8. The resulting energization of. relay coil I6I will cause mercury switch I46 to be tilted to open position thereby disconnecting beacons 6| and 62 from both generators except through the resistance element or lamp I61.

When, however, the temperature of either unit becomes high enough for proper operation thereof, its thermostatic controller 40 or 40a will open mercury switch 46 or 460. thus deenergizing relay coil I6I, causing the mercury switch I46 to be moved to closed position, thereby connecting beacons 6| and 62 to the load wire I46 leading from the clock mechanism 10.

Operation with the parts in. the position shown, the switch arm 11 is disengaged from contact segments 19 and 80 and the contact arm 18 is disengaged from contact segments 82 and 83. The

' starting resistance 85 is therefore not in circuit with the output terminals of either generating unit. Also, the storage battery is disconnected r from the driving motor 90 and also from the relay coil I6I of the load relay I60. The load relay' coil is thus at this time deenergized and the mercury switch I46 is in closed position. At this time also it will be noted the switch arm 91 of the load selector switch is not engaged with either contact segment I H or I42. The beacons 6I and 62 are therefore disconnected from the output terminals of both generating units and the generating units are out of operation.

In the positionshown, the switch arms 11 and 18 are about to engage their respective contact,

segments. Shortly before sunset the switch arm 11 will engage contact segments 19 and 80, and simultaneously the switch arm 18 will engage'the contact segments 82 and 83. Engagement of switch arm 11 with contact segments 19 and 80 will cause energization of the driving motor 90, the energizing circuit being as follows: positive terminal storage battery I8, wire 20, contact segment 19, switch. arm 11, contact segment 80, wire 2, wire III, wire IIO, contact segment IOI, switch arm 96, contact I 00, wire II5, series fields I I6 of motor 90, armature 90a, wire I I1, resistance I I8, wire I I9 and wire 24 to the negative terminal 23 of storage battery I8. Engagement of the switch arm 11 with contacts 19 and 80 will also thrown across the output terminals I3 of generating unit I, this circuit being as follows: positive terminal I3, wire I36, contact segment I33, arm 94, contact I32, wire I35, contact segment 82, switch arm 18, contact segment 83, starting resistance 85, wire 86, wire 63, wire 38 and wire 31 to the negative output terminal I3. At this time, therefore, the motor 90 will be rotating shaft 93 and contacts 94, 95, 96 and 91 in a counter-clockwise direction and the starting resistance will be thrown across the output terminals oi generating unit I causing the generator 4 to operate as a motor to start the engine 3. The speed of motor 90 and the gear train 12 are designed so as to cause a second period to elapse before the switch arm 96 will disengage from contact segment IN to break the motor operating circuit.

IN and on to the contact segments I02 and I05,

, the switch arm 94 will simultaneously ride off contact segment I33 thus disconnecting the starting resistance 85 from the generator terminals. At the same time, however, the switch arm 91 will engage the contact segment I4I this causing the beacons GI and 62 to be connected across the generator terminals of generating unit I through the resistance or lamp I61, this circuit being as follows: positive output terminal I3, wire I36, wire I43, contact segment I4I, switch arm 91, contact segment I40, wire I45, lamp I61, wire 61, wire 68, beacon 62, wire 66, and from wire 61 to beacon 6I, wire 65, wire 63, wire 38, and wire 31 to negative output terminal I3. It will be seen, therefore, that simultaneously with disconnecting the starting resistance 85 from the generator terminals, the lighting load in series with resistminals, this loading causing continued operation of said generating unit.

At the same time as the switch arm 96 moves to horizontal position the switch arm 95 will engage with the contact segment I5I. If during the 15 seconds starting interval previously mentioned the motor has started and the generator voltage has come up to the proper value, the relay coil of potential relay 13 will now be energized and this will act to pull the switch arm I23 irom the con tact I22. The circuit for energizing the potential relay 13 is as follows: positive output terminal I3 of generating unit I, wire I36, wire I43, contact segment I4I, arm 91, contact I40, wire I45, wire I54, contact I50, arm 95, contact segment I5I, wire I80, mercury switch 56 of safety controller 50, wire I8I, wire I82, coil of relay 13, wire I83, wire 63, wire 38, and wire 31 to the negative out.- put terminal I3 of generating unit I. If the terminal voltage of the generator has caused relay ance I61 will be thrown across the generator ter- 13 to pull in and disengage switch arm I23 from contact I22 by the circuit just mentioned, the contact I02 will be deenergized. Therefore, when contact arm 96 moves from contact I00 to the dead contact I02 the energizing circuit for the motor 90 will be broken and the motor will stop at this point, thus causing continuous operation 0 generating unit I. r

If, however the voltage fails to build up during the 15 second starting period, the potential relay II will not be energized. The switch arm I23 therefore would continue to engage contact I22, this connecting the contact segment I 02 with the positive side of the storage battery in the manner previously described. Therefore, when switch arm 86 rides oil contact IOI and on to contact I02, the motor 90 will continue to be energized, and rotation of shaft 93 and the switch arms 54, 95 and 98, and 91 will continue. At this time, it will be remembered that the starting resistance has been cut out by disengagement of switch arm 94 from contact I33, and the beacons BI and 62 in series with lamp I61 have been thrown across the generator output terminals I3. This condition will exist for the fifteen seconds required for the switch arms to be rotated through the second quadrant. Due to the lamp IE1 being connected in series with the beacons GI and 62 at this time, the beacon light load is not placed on the generators. Hence this second fifteen second period permits the engine I to start if it did not start during the fifteen second starting period, and also gives an additional time in which the generator voltage may build up if the engine had started in the first period but no voltage had built up. If lamp I 61 were not in series with the beacons 6| and 02, the full lighting load would have been thrown across the generator terminals during this second fifteen second period. While this would be somewhat satisfactory in warm weather, it would be entirely unsatisfactory in cold weather, as the engine 3 would be below proper operating temperature and would stall instead of assuming the load. Also without lamp ISI in series with the beacons 6 I and 52, this second fifteen second period would not be an additional starting period as the engine would be incapable of starting under load. It will be seen therefore that the arranging of lamp IGI in series with the beacons provides an additional period in which the engine may start, and further provides a period in which the generator voltage may build up without assumption of load, in the event that the engine started during the first fifteen second period, and the generator voltage failed to immediately build up. If during the second fifteen second period, the generator voltage builds up, the potential relay coil will be energized, this causing opening of the operating circuit of motor 30 and stopping of rotation of shaft 33 and the switch arms 94, 95, 96, and 91, this permitting continuous operation of generat- "ing unit I.

Should motor 3 fall to start or to continue to operate with the lamp load during this second 15 second period. the relay coil I2 will continue to be deenergized thus causing switch arm I23 to remain in engagement with contact I22 which in turn causes motor 30 to be operated. When switch arm 36 disengages contact segment I02 it rides upon the contact segment I03. As the, contact segment I03 is connected in parallel with the contact segment IN, the motor 90 will be energized independently of the voltage relay. At the same time that switch arm 9 rides off contact segment I02 and rides upon contact I03, the switch arm 34 will engage the contact-segment I34, the switch arm 95 will disengage the contact segment I5I, and the switch arm 91 will disengage the contact segment I. Engagement of switch arm 34 with contact segment I34 will place the starting resistance 05 across the output terminals I4 of generating unit 2 by the following circuit: positive output terminal I4, wire I31, contact segment I34, switch arm 94, contact I32, wire I35, contact -82, switch arm II, contact 83, starting resistance 85, wire 36, wire 63 and wire 64 to the negative output terminal I4. Disengagement of switch arm 91 from contact I4I will break the load circuit across the output terminals of the generating unit I. It should therefore be apparent that when switch arm 96 rides upon the contact I03 the load will be disconnected from generating unit I, and the starting resistance placed across the output terminals of generating unit 2. The engagement of switch arm 96 with contact I03 therefore provides a 15 second starting period for generating unit 2 of exactly the same nature as described in connection with generating unit I.

It should be noted that at the end of this 15 second starting period, the switch arm 94 will ride oil contact I34 thereby breaking the starting resistance circuit. Simultaneously the switch arm 97 will ride upon the contact I42 thus placing the lighting load in series with the lamp bulb or resistance I61 across the output terminals of generating unit 2. If during this 15 second starting period the generating unit 2 has started, the voltage relay I3 will be energized by the following circuit: positive output terminal I4, wire I31, wire I44, contact I42, switch arm 91, contact I40, wire I45, wire I54, contact I50, switch arm 95, contact I52, wire I84, mercury switch 56a, wire I85, wire I82, relay coil I3, wire I83, wire 63 and wire 64 to negative output terminal I4. Energization of relay coil I3 will cause deenergization of the contact I04. Therefore when switch arm 96 rides upon contact I 04, the motor will stop. At this time, therefore, the generating unit 2 will be left in operation.

If instead of starting during the first 15 second period the generating unit 2 fails to start or if the generator voltage fails to build up, the relay coil 13 will not be energized and the contact segment I04 will therefore be energized, this causing further operation of motor 90 and providing a second 15 second period in which angine 3a may start, and/or in which the generator voltage may build up, this period being of exactly the same nature as the corresponding period for generating unit I, which has been previously described from motor 2. If during this period the motor starts and/or the voltage builds up, the relay coil I3 willbe energized thereby deenergizing contact I 04 and causing motor 90 to stop, thus permitting continuous operation of generating unit 2. Should generating unit 2 fail to start during this 15 second period, the switch arms 94, 95, 96 and 91 will reassume the position shown in the drawings thereby again attempting to start generating unit I.

It should be apparent that if either generating unit I or 2 is operating and then'for some reason fails, the generator terminal voltage will fall, thus deenergizing the relay coil I3, this causing the clock I0 to recycle to cause starting of the other generating unit. It should also be apparent that the energizing circuit for relay coil I3 will be caused by the selector switch 90 to pass through the mercury switch 56 or 56a of the safety controllers 50 or 50a. Thus should the engine of the generating unit in operation overheat, the energizing circuit for relay coil I3 will be broken this causing recycling of the apparatus to start the other generating unit.

From the foregoing it will be apparent that the system at sunset will operate to start either the generating unit I or the generating unit 2. It should also be apparent that when either generating unit I or the generating unit 2 is in operation, the switch arm 96 will be engaging either the contact segment I05 or'the contact segment I06. vided for the purpose of shutting down whichever unit happens to be operating at sunrise, which operation will now be described in detail. At sunrise the switch arm 18 will disengage from the contact segments 82 and 83 thereby completely disconnecting the starting resistance .05 from each generating unit regardless of the position 'of the starting load selector 94. At the same time the switch arm 11 will ride on the contact segment 80, this action disconnectin the positive terminal I9 of the storage battery I8 from the contact segments |I and I03. A short time thereafter, the switch arm 11 'will engage the contact 8|. This will complete an energizing circuit for motor 90 as follows: positive terminal I9 of storage battery I8, wire 20, contact segment 19, switch arm 11, contact 8|, wire I30, wire I30a or I3I, contact segment I or I06, switch arm 96, contact I00, wire II5, motor 00,

.choking resistance H8, wire H9 and wire 24 to the negative terminal 23 of storage battery I8. This will cause motor 90 to be operated until the switch arm 96 disengages thecontact |05- or I06 whichever it happened .to be on). As the contacts MI and I03 have now been deenergized by disengagement of switch arm 11 from contact 80, the motor 90 will stop with the switch arms 94, 95, 96 and 91 in a vertical position. v In such position the switch arm 91 disconnects the-beacons from both generators, and the switch arm 94 is set for connecting the starting resistance across the generating unit which had not previously been operating so that such unit may be started at sunset. a

As indicated hereinbefore. the load relay I60 acts to prevent the beacons 6| and 62 from being directly connected across the generating terminals of the unit which happens to be operating until the temperature of the engine driving that unit has raised sufiiciently to permit such engine to assume the lighting load without stalling. As pointed out previously, the relay coil |6| of the load relay I60 is connected mercury switches 46 and 46a of'the temperature responsive devices 40 and 40a, these devices being arranged so that their switches remained closed so long as the temperature of their respective engines is below a proper operating value. When, however, the temperature of the generating unit which is operating reaches a proper value, the mercury switch 46 or 46a will be moved to open position thus breaking the energizing circuit for relay coil ISI. This will cause lever I62 to be moved in a counterclockwise direction under the action of gravity or springs, not-shown, thereby tilting the mercury switch I46 to closed position, this shunting out the resistance or lamp I61 and connecting the beacons directly across the terminals of the operating generating unit. It should therefore be apparent that the entire load of the beacons 6| and 62 cannot be connected across the terminals of the operating generating unit until the temperature of that unit has reached a proper operating value. By this arrangement stalling of a started generating unit due to the lighting load being thrown upon it too early is prevented.

It should be noted that due to the relay coil ,I6I or load relay I60 being connected by wires These contact segments are proin series with the no and M2 to the battery switch formed by switch arm 11 and contacts 19 and 00, the relay Y I60 will be completely deenergized whenever the battery switch is open. Therefore, when the clock mechanism is not calling for engine operation, there can be no flow of current in the load relay energizing circuit, and hence there is no drain on the battery I0 when neither unit is in operation. It should aiso be noted that due to use of a relay which is normally closed as the load relay I60, this relay need be energized only during the warming up period of one of the engines3 or 30.". The current'consumption by relay I60 therefore will be a minimum.

Referring now to Figure 2, this figure shows a system identical with that illustrated in Figure 1, with the exception that the arrangement of the load relay and the controllers therefor is somewhat modified. inside the clock mechanism have not been illustrated for the reason that such has been described in detail in connection with Figure 1. Also the controllers 50 and 50a and their connections with the clock mechanism 10 have been omitted for the sake of clearness in illustration. It will beiiunderstood, however, that these controllers will be connected in the same manner shown in detail in Figure 1.

The load relay |60a which is interposed in the wire H45 leading to the beacons 6| and 62 and which corresponds to the load relay I60 of Figure 1 is similar in construction to said relay I80 except that it is arranged so that the mercury switch M611 is in 'open position when the relay coil |6|a1 is deenergized. When the relay i6|a is energized, it causes the lever I620. to be moved in a counterclockwise direction about its pivot I63a, this causing the mercury switch carrier I650 to be tilted about its pivot I660. to move the mercury switch H611 to closed position.

The generating unit I is provided with a thermostat 40 which corresponds to the thermostat 40 in Figure 1, and the generating unit 2 is In this figure the connections ,1

provided with a similar thermostat which corresponds to thermostat 40a of Figure 1. These thermostats each consist of the same elements as pointed out in connection with the thermostats 40 and 40a of Figure ,1. The arrangement of thermostats 40', however, is reversed from the corresponding elements of Figure 1, in that the mercury switches 46b and 460 are arranged to 46b and 460. The other terminals of saidmer:

cury switches are connected by wire I93 to the of the storage battery. |0. It should thus be apparent that the mercury switches 46!) and 46c are connected in parallel with respect to the relay -coil' |6|a. Therefore, when both engines are cold, both mercury switches 46b and 460 will be in open position, this resulting in the relay coil I6Ia being deenergized. At this time the mercury switch |46a will be in open position this placing the resistance I61 in series with the beacons 6| and 62, thereby preventing the full lighting load from ,being thrown across the output wire 24 which leads to the negativeterminal 23 terminals of the ,operating generating unit.

When however, the temperature of the engine of the operating unit reaches a proper value, either the mercury switch D or the mercury switch 46c will be moved to closed position, this causing the relay coil I iii to be energized. This causes tilting of mercury switch Ilia to closed position, thereby directly connecting the beacons 5i and 62 to the operating unit. It should therefore be apparent that this arrangement will likewise prevent beacons GI and 62 from being directly connected to whichever generating unit is started until the temperature of that unit has reached a proper operating value.

It will be apparent that many changes will suggest themselves to those skilled in the art, and therefore I wish to be limited only by the scope of the appended claims and the prior art.

I claim as my invention:

1. In a system of the class described, a prime mover, load means actuated by said prime mover, variable power transmission means interposed between said prime mover and said load means for transmitting power from said prime mover to said load means, automatic starting means for said prime mover, a controller for said variable power transmission means, means for automatically responding to an internal condition within the prime mover which is indicative of the prime mover's ability to operate satisfactorily (as distinguished from an output condition of said prime mover) said last mentioned means actuating said controller for the variable power transmission means and being arranged to position said controller in a manner to diminish the transmission of power from said prime mover when said condition is at a value indicating that the engine is not in condition forsatistactory operation, while increasing the transmission of power from said prime mover to a maximum when said condition is at a value indicating that the engine is in condition for satisfactory operation.

2. In a system of the class described, a prime mover oi. the internal combustion type, load means actuated by said prime mover, starting means for said prime mover, means for selectively connecting said load means to said prime mover and for disconnecting said load means therefrom, said last mentioned means including a thermostat responsive to the temperature of said prime mover, said thermostat being arranged to at least partly disconnect said load means from the prime mover untll'the temperature of said prime mover reaches a predetermined value.

3. In an automatic lighting system, in combination an engine driven generator unit, start ing means for said engine of the type actuated by the placing of a load across the terminals of said generator, a lighting unit, a circuit for connecting said lighting unit with said generator to energize said lighting unit, a starting resistance,

a circuit for connecting said starting resistance across said generator to cause starting of said engine, a selector switching mechanism arranged to selectively open one of said circuits and close the other, automatic means for positioning said switching mechanism to close the circuit through said starting resistance when said engine is out of operation, and for positioning said selector switching mechanism to close the circuit through the lighting unit when said engine is in operation, a main switching mechanism for opening both of said circuits to place said engine out of operation, timing means for controlling said main switching mechanism to cause operation oi.

said engine at predetermined times, and means responsive to an operating condition of said engine for preventing complete connection of said lighting unit with said generator until the operation of said engine is sufficiently satisfactory to carry the load imposed thereon by said lighting unit.

4. In a system of the class described, in combination an engine driven generator unit, starting means for said engine of the type actuated by the placing of a loadvacross the generator terminals, a main electrical loading means for said generator, a circuit for connecting said loading means to said generator, a starting resistance, a circuit for connecting said starting resistance across said generator to cause starting of said engine, switching means for said circuits for opening both circuits or selectively placing said starting resistance or said main load across said generator terminals, timing means for controlling said switching means to place said generator into or out of operation, and means responsive to an operating condition of said engine for preventing complete connection of said main load across said generator until the operation of the engine is sufiiciently satisfactory to carry the load im; posed thereon by said main loading means.

5. In a system of the class described, in combination, an engine driven generator unit, starting means for said engine of the type actuated by the placing of a load across the generator terminals, a main electrical loading means for said generator, a circuit for connecting said loading means to said generator, a starting resistance, a circuit for connecting said starting resistance across said generator to cause starting of said engine, switching means for said circuits for opening both circuits or selectively placing said starting resistance or said main load across said generator terminals, timing means for controlling said switching means to place said generator into or out of operation, and means responsive to the temperature of said engine for preventing complete connection of said main load to said generator until the engine temperature has reached a predetermined value.

6. In a system of the class described, in combination, an engine driven generator unit, control means for said generator unit of the type causing starting of said engine when a load is placed across the generator terminals and causing stopping of the engine when the load is removed, loading means for said generator, a circuit for connecting said loading means to said generator, a starting resistance, a circuit for connecting said starting resistance across the gen-: erator to cause starting of said engine, a selector switch mechanism arranged when in starting position to open the load circuit and to close the starting resistance circuit, and when in running position to open the starting resistance circuit and to close the load circuit, automatic means for positioning said selector switch mechanism, a main switching mechanism for opening both of said circuits regardless of the position of said selector switch mechanism to place said engine into or out of operation, timing means for coritrolling said main switching mechanism to automatically place said generator into and out oi operation at predetermined times, a switch in said load circuit, means responsive to an operating condition of said engine for holding said switch open until the operation of the engine is suiiiciently satisfactory to carry the load, and resistance means shunting said switch for imcausing starting of said posing a slight load on said generator when said switch is open to retain said generator unit control means in running position.

7. In a system of the class described, in combination, an engine .driven generator unit, control means for said generator unit of the type engine when a load'is placed across the generator terminals and caus ing stopping of the engine when the load is removed, loading means for said generator, a circuit for connecting said loading means to said generator, a starting resistance, a circuit for con necting said starting resistance across the genera-, tor to cause starting of said engine, a selector switch mechanism arranged when in starting position to open the load circuit and to close the starting resistance circuit, and when in running posttion to open the starting resistance circuit and to close the load circuit, automatic means for positioning saidselector switch mechanism, a main switching mechanism for opening both of said circuits regardless of the position of said selector. switch mechanism to place said engine into or out of operation, a switch in said load circuit, means responsive to an operating condition of said engine for holding said switch open until the operation of the engine is suiiiciently satisfactory to carry the load, and means for imposing a slight load on said generatorwhen said switch is open to prevent said control means for said generator unit from causing stopping of said unit when said switch is open.

8. In a system of the class described, in combination, an engine driven .generator unit, control meansfor the engine of said unit of the type causing said engine to automatically start when a load is placed across the generator and to stopv when the generator load is removed, automatic means for loading the generator, switching mechanism in the load circuit, means responsive to an operating condition of the engine for closing said switching mechanism when the operation of said engine is sufficiently satisfactory to carry the load, and auxiliary loading means controlled by said switching mechanism for preventing said engine control means from stopping the engine when said switching mechanism is open.

9. In a system of the class described, in com-. bination, an engine driven generator unit, control means for the engine of said unit of the type causing said engine to automatically start when a load is placed across the generator and to stop when the generator load is removed, automatic means for loading the generator, switching mechanism in the load circuit, means responsive to the temperature of the engine for closing said switching mechanism when the temperature of said engine reaches a predetermined value, and auxiliary loading means controlled by said switching mechanism for preventing said engine control means from stopping the engine before closure of said switching mechanism.

10. In a system of the class described, in combination, an engine driven generator unit, control means for the engine of said unit of the type causing said engine to automaticallystart when a load is placed across the generator and to stop when the generator load is removed, automatic means for loading the generator, switching mechanism in the load circuit, means responsive to an operating condition of the engine for closing said switching mechanism when the operation of said engine is sufllciently satisfactory to carry the load, and auxiliary loading means for preventing said engine control means from stopping the engine when said switching mechanism is open.

11. Ina-system of the class described, in cornbination, a prime mover of the internal combustion type, a generator connected to said prime mover to be driven thereby, means for controlling the load carried by said generator, means responsive to the'temperature of said prime mover for positioning said controlling means, said temperature responsive means cooperating with said controlling means to cause said generator to assume no more load than canbe satisfactorily carried by said prime mover to prevent stalling thereof.

12. In a system of the class described, in combination, a prime mover, a generator connected to said. prime mover to be driven thereby, means for controlling the load carried by said generator, said controlling means comprising a normally closing said switch when the temperature of said prime mover rises above a predetermined value.

13. In a system of the class described, in combination, a first engine driven generating unit, a second engine driven generating unit, a common electrical load for the two generating units, means for selectively starting the engine of either unit, means for selectively connecting said load to either generator, said selective connecting means acting to connect the load to the unit selected by said starting means, and means including a device responsiveto an operating condition of engine of the selected unit forpreventing complete connection of the load to the selected unit until the operation of the engine is sufficiently satisfactory to enableit to carry the load.

l4.v In a system of the class described, in combi I selected by. said starting means, and means including a device responsive to the temperature of the engine of the selected unit for preventing complete connection of the loadto the selected unit until the temperature of the engine reaches a predetermined value.

15. In a system of the internal combustion engine, a second internal combustion engine, means for selectively starting either engine, load means, means for selectively connecting said' load means to either engine, said selective connecting means acting to connect said load means to the engine selected by said starting means and including a device responsive to.an operating condition of the selected-engine for preventing connection of .the load means to said engine until the operation of the latter is sufficiently satisfactory to carry the load imposed by said load means.

class described, a first second engine driven 17. In a system of the class described, in combination, a first engine driven generator unit, a generator unit, a common electrical load on the two generating units, means for selectively starting the engine of either unit, means for selectively connecting said load to either generator, said selective connecting means acting to connect the load to the unit selected by said starting means, and means for preventing the load from being completely connected o said selected unit until the engine of said unit reaches a proper operating condition, said last named means comprising a normally open switch in the load connecting means, and control meanslor said switch for closing said switch upon either engine reaching a proper operating condition.

preventing the load from being completely connelted to said selected 'unit until the engine of said unit reaches a proper operating condition, said last named means comprising a normally closed switch, and means tor maintaining said switch in open position until. one 01 reaches proper operating condition.

CE W. NESSELL the units 1 

